Claudio Succa <claudio.succa.ml@pertel.it> writes:
> (Not to reinvent the wheel, do you know where I could find a suitable
> function to use in the trigger?)
No, but it should be pretty trivial to write. Just set up a BEFORE
UPDATE trigger that compares OLD.ts_field against NEW.ts_field and
does a RAISE ERROR if they're different. The PL/pgSQL docs have a few
decent examples of how to write a trigger function.
-Doug